In the pursuit of a developable form of a solid, orally-administered pharmaceutical compound, a number of specific features are sought. Although an amorphous form of a pharmaceutical compound may be developed, compounds having high crystallinity are generally preferred. Often such highly crystalline compounds are salts.
International Patent Application Number PCT/US2013/77235 describes a series of compounds which are indicated as inhibitors of protein arginine methyltransferase 5 (PRMT5), and which are indicated as being useful in the treatment of PRMT5-mediated disorders. Specifically disclosed in that application is the compound (S)-6-((1-acetylpiperidin-4-yl)amino)-N-(3-(3,4-dihydroisoquinolin-2(1H)-yl)-2-hydroxypropyl)pyrimidine-4-carboxamide (hereinafter “Compound A”). Identification of a stable, crystalline form of such compound with suitable properties for oral administration would be highly desirable for the treatment of PRMT5-mediated diseases.